I'm just sort of spitballing here, getting ideas down on paper and giving myself a prod to keep working on this.

I've been working on coming up with a cost effective (ie. cheap), yet strong and stable design for a 3D printer class. The price point for the class has been $400 but I think I can get it even lower. We're nearly over some of the main hurdles, which have been an electronics package for $50 or less, getting extruder nozzles for under $50 each, sourcing stepper motors and other vitamins to avoid paying exorbitant amounts of shipping, and using a design that requires as few vitamins as possible.

I found a design that I like called the Graber i3, which is a derivative of the Prusa i3, if you want to check it out online. The entire frame has been designed to be laser cut and only requires a handful of nuts and bolts. There are only a few pieces that are required to be printed, like the extruder portion. I'm going to try and get some laser time and do a test run, but I'm thinking this frame will go together really quickly and require next to no tweaking and adjusting to make sure it's square.

Another part I haven't gotten quite sorted out yet is the heated bed. I can look into ordering them from someone that makes them or I can try making them on the laser cutter. I may try it on the laser just to see how well that works. I'm also thinking about leaving out the power supply, as many people have an old or dead PC laying around they can scavenge a PSU from. I could also offer them for an additional cost to folks taking the class.

I'm considering doing a whole series of classes or workshops that I can offer to people either building a 3D printer or just want to take a class on that particular subject. I think I mentioned this somewhere but I can't remember where I left it.

List of classes:-Soldering electronics. Populate your own PCB for your printer, or watever other project you have.-Laser cutter basics. Learn to cut your own printer frame.-3D printer frame assembly. Including wiring and calibrating.-3D modeling. Design and print your own stuff, could include using image capture. Need someone that's proficient in free or cheap modeling software. -PCB design, laser cutter and toner transfer methods.-Extrude your own filament. Or we could build an extruder (I got plans) if Doug doesn't feel comfortable letting a lot of people use his Filabot.

The first 3 will be included as a package for people that are actually building a printer, but I'd like to leave it open to others that aren't but want to learn laser cutter basics and soldering.

I don't know if I'll write up anything for a lot of these classes, maybe eventually. The first class needs to get underway ASAP and I'll keep notes on areas that should actually be documented, otherwise it'll be freeform and respond to the needs of the attendees. (That's just my way of admitting that I'm lazy.)

Post up ideas or comments. I know not too many people use the forum, but I find it's a great way for me to monitor my own projects. And I know I'll get some good feedback from you few that still come here.

I'm fine with people using the FilaBot from the Kickstarter, but we first have to work out how to get consistent filament. A major part of that will be to get a spooling system working so the stress on the extruded filament is consistent. It looks like the automatic spooling system that FilaBot was selling is sold out (http://www.filabot.com/collections/comp ... ing-system) but we might be able rig up our own system?

Also the temperature of the plastic can affect diameter it appears from test runs today during the Seward Art Crawl event at the Hack Factory.

The sparse instructions that came with the FilaBot say: "Set the temperature for the plastic that you are extruding and wait until the extruder is headed up. Only extrude when the desired temperature is reached. If temperature is not reached then it can damage mechanical components. the temperature controller measures a little lower than the actual temperature. ABS extruding temperature can range from 150C to 180C. PLA extruding temperature can range from 130C to 160C. Raising the temperature up and down to get the right setting will have to be done."

I took som measurements yesterday and it seemed to be consistently right around 3.5mm when extruding straight to the floor. The problem I had was somebody would come talk to me and it would invariably stay on the bed of the machine and make a mess. I'd say it definitely needs some sort of consistent tension to keep the filament a smaller diameter. We could also try using a smaller hole so when it expands it expands to the right diameter.

Take a look at the most recent Lyman development, he's added water cooling, a measuring device and a spooler. I think we could easily add a spooler and just use a potentiometer to adjust the spool rate. I have four 24V motors, 18rpm, 1.5A I nabbed off the up for grabs I was intending on turning into my own filament extruder and spooler, but we can try making a spooler out of one.

The idea I have for a regrinder is a relatively low rpm spindle with several small, low tooth count blades with a hopper like the one on the filabot. Something like a couple of dual-saws would be ideal, just slow them down a bit.